Introduction and objectives: This study obtained preliminary evidence for the validity of the internal structure and invariance of the Social Support at Work Scale, an integrated measure in the battery of UNIPSICO tests for the evaluation of psychosocial factors of resources. Material and method: 177 engineers participated (74% males) aged 19 to 64 years old from the city of Lima, Peru. The internal structure was examined through two models: the nonparametric approach of the Item Response Theory and SEM modeling; the differential functioning of items according to sex was tested and the reliability was estimated with Cronbach's alpha and Omega coefficients. Results: A strong one-dimensional structure of the Social Support at Work Scale was verified with both approaches (factor loads between.46 and.82); no differential functioning was detected with respect to sex and the reliability coefficients were acceptable and very similar (.79). Conclusions: The Social Support at Work Scale presents satisfactory results in terms of validity and reliability and opens the door to future research in the Peruvian context.